An Individualized Approach to Skin Conductance Assessment during Execution of Tasks of Different Complexities

Researchers use different approaches to analyze changes in skin conductance. At the same time, individual differences observed in both the initial values of skin conductance and response to stimuli do not allow comparing the responses of different subjects to the same impact. An individualized approach to the assessment of psycho-emotional stress has been developed using the real-time skin conductance index during continuous performance of a task with different levels of complexity. The participants, 18 second-year students at the actors' high school, performed a simple task (expressive reading aloud of a simple text) and a difficult task (expressive reading aloud of the text inverted 180°). During the task, the skin conductance in the participants was continuously recorded. We revealed a change in the parameters of skin conductivity depending on the complexity of the task, both in comparison with resting state (baseline) and with simple and complex stages of the study. However, the individual skin conduction curves in the subjects differed greatly. A method for assessing the individual differences in parameters of skin conductance was proposed based on ranking by categories of values during continuous performance of tasks with different levels of complexity. This method allows comparing the levels of cognitive load in participants with different initial levels of skin conductance due to transition from the absolute to relative values at time intervals that are important for the researcher.

The Main Causes and Mechanisms of Increase in Cardiac Troponin Concentrations Other Than Acute Myocardial Infarction (Part 1): Physical Exertion, Inflammatory Heart Disease, Pulmonary Embolism, Renal Failure, Sepsis

The causes and mechanisms of increased cardiac troponin T and I (cTnT and cTnI) concentrations are numerous and are not limited to acute myocardial infarction (AMI) (ischemic necrosis of cardiac myocytes). Any type of reversible or irreversible cardiomyocyte injury can result in elevated serum cTnT and cTnI levels. Researchers and practitioners involved in the diagnosis and treatment of cardiovascular disease, including AMI, should know the key causes and mechanisms of elevated serum cTnT and cTnI levels. This will allow to reduce or completely avoid diagnostic errors and help to choose the most correct tactics for further patient management. The purpose of this article is to discuss the main causes and mechanisms of increase in cardiac troponins concentrations in frequently occurring physiological (physical exertion, psycho-emotional stress) and pathological conditions (inflammatory heart disease, pulmonary embolism, chronic renal failure and sepsis (systemic inflammatory response)) not related to myocardial infarction.

Response of the Hemostatic System to Acute Vital Stress in Rats

We studied the effect of acute vital stress on the parameters of the hemostasis system in young and old Wistar rats. The psychotraumatic effect was simulated as a situation of emotional stress at the sight of a predator (Indian python) catching and eating a conspecific. In young rats, acute vital stress was followed by inhibition of platelet aggregation, hypercoagulation by the external pathway and final stages of plasma hemostasis, and a decrease in fibrinogen and antithrombin III levels against the background of fibrinolysis activation. In old animals, increased platelet count with reduced aggregation capacity, hypocoagulation by the internal pathway of the plasma hemostasis activation, signs of thrombinemia (a 2-fold increase in soluble fibrin-monomer complexes), an increase in antithrombin III, and inhibition of the fibrinolytic system were observed. Age-related changes in the hemostasis parameters in rats were determined before and after stress exposure.

[Transcranial electrostimulation and serotonin laser phoresis in the athletes experiencing a combined effect of fatigue and psycho-emotional stress]

RATIONALE

At sports submaximal loads accompanied by muscle fatigue due to metabolic transformations, the conditions are created for the development of combined endogenous and exogenous emotional stresses. An important role in the development of stress is played by the state of adaptation mechanisms, in which sintoxic and catatoxic programs are involved, as well as the GABA-dopaminergic system. There is insufficient information on the possibilities for reducing the manifestations of stress.

PURPOSE

The objective of the presser study was to estimate the possibilities for the prevention of the development of psycho-emotional stress with the use of transcranial electrostimulation in the combination with serotonin laser phoresis.

METHODS

The assessment of the psychological status before and after transcranial electrostimulation in the combination with serotonin laser phoresis was performed in 96 athletes who were engaged in weightlifting and athletic gymnastics, as well as in 37 athletes comprising the control group in the state of sparing rest. Transcranial electrostimulation was carried out during 14 days. The laser phoresis of serotonin was conducted with the application of the Matrix device and transcranial electrostimulation with the use of the Magnon-DKS apparatus. The assessment of the psychological status was carried out based on the Hospital Anxiety and Depression Scale (HADS) and the results of the well-being-activity-mood (WAM) questionnaire and in accordance with the Hildebrandt index, and the Spielberger-Hanin test.

RESULTS

The two-week course of exposure to transcranial electrostimulation and serotonin laser phoresis of the patients comprising the main group resulted in a faster stabilization of the psychological status than in the control group. This effect was due to the multi-component involvement of the athletes in the adaptation programs including the management of homeostasis and the influence on the GABA-dopaminergic system via the serotonin and opioidergic mechanisms.

CONCLUSION

The results of this study give reason to recommend the proposed method of transcranial electrostimulation and serotonin laser phoresis for the use in sports medicine.

[Nerve Growth Factor in Patients With Arterial Hypertension: Neuropsychical, Hemodynamic, Metabolic Relationships]

AIM

To investigate the changes of serum nerve growth factor (NGF) level in patients with arterial hypertension (AH) and obesity in dependence on the degree of psycho-emotional stress and physical activity.

MATERIALS AND METHODS

We examined 76 male patients with stage I and II AH with mean age 46.75±0.56 years (36 patients with and 40 without obesity). Control group consisted of 26 individuals without AH, obesity, and cardiovascular diseases. All patients underwent ambulatory blood pressure (BP) monitoring. Serum concentrations of NGF β-subunit and cortisol were determined by enzyme linked immunosorbent assay. For assessment of levels of psycho-emotional stress, reactive and personal anxiety, and physical activity we used Psychological Stress Measure (PSM-25), the Spielberger-Khanin questionnaire, and brief International Physical Activity Questionnaire (IPAQ), respectively.

RESULTS

Level of NGF in patients with AH and obesity (0.94±0.28 ρg/ml) was higher than in non-obese patients with AH (0.21±0.06 ρg/ml; p=0.018) with highest figures in patients with insufficient physical activity and high level of psychoemotional stress. In all groups of patients there was unidirectional reverse correlation between serum NGF and cortisol levels. According to ambulatory BP monitoring, NGF level was inversely proportional to systolic and diastolic BP variability in patients with AH and obesity and in the control group. Reduced serum concentration of NGF was associated with increased levels of reactive and personal anxiety.

CONCLUSION

Obtained data suggests that NGF plays an important role in complex multifactorial interactions between neuropsychic, cardiovascular and metabolic processes.